Relatively small networks, such as local area networks (LANs), may use multicasting. Multicasting includes, for example, transmitting a broadcast packet or a multicast packet to all the communication devices connected to the network.
For example, a server may transmit a broadcast packet to multiple communication devices, requesting responses from those devices to the broadcast packet. In this case, the server receives response packets from many communication devices.
If many communication devices transmit response packets to the server at a time, the packets may collide with one another on the network, increasing the likelihood of errors occurring in the communication. Techniques have been proposed to allow, for example, such multiple communication devices to transmit response packets to the server at different times by time sharing.
Patent Literature 1 describes communication in which a polling packet is transmitted from an information processing unit and is received by multiple mobile stations. Each mobile station transmits a response to the information processing unit by using a timeslot that has been determined based on random numbers.
Patent Literature 1: Japanese Unexamined Patent Publication No. 8-340573
The technique described in Patent Literature 1 reduces the likelihood of collisions between responses transmitted from multiple mobile stations. However, despite its use of random numbers, this technique can increase the likelihood of response collisions if the response period assigned to each mobile station is short.